A brief history of asthma and its mechanisms to modern concepts of disease pathogenesis

A soft systems approach of asthma management in children based on therapeutic education and e-learning

One of the most common respiratory chronic diseases is asthma, with 5-16 % of world prevalence. In chronic disease, prevention, diagnosis, management, and palliation are the strategies for a care model; the patient-self management is fundamental with the so-called therapeutic education (TE) to train the patient in the necessary skills. The challenge of TE grows when the patient is a child or a person with special needs, even more in public health care in low- and middle-income countries. This is a problematic human situation, that needs soft system thinking. In this research, the analytic hierarchy process was used to determine the perceived importance of the factors that affect children's asthma health care in a public health institution in Mexico. The soft systems methodology (SSM) was applied to learn about the disease self-management, in order to obtain activities models and an action plan. According to AHP, human resources and education were percived as the most important among the factors that affect children health care within the institution. The perceived importance of two main subfactors (human resources training and TE) was around 34 %, which emphasizes the need to generate strategies for the improvement of the education of patients and health care providers. In MSS, the rich vision, the CATWOE, the root definition, and an activities model were proposed, including the application of an instructional design methodology (ADDIE) for the development of learning objects of asthma for children. Desirable and feasible actions and recommendations include the update of the national clinical practice guides, the use of control measures such as the Asthma Control Test, and a daily asthma diary to register the daily status of the breathing capacity, the drug administration, and the potential trigger events. The proposed model can be used as part of a systemic patient-and-family centered approach for chronic care model (CCM), particularly in diseases unsuitable for prevention interventions.

Modeling the enigma of complex disease etiology

BACKGROUND

Complex diseases often present as a diagnosis riddle, further complicated by the combination of multiple phenotypes and diseases as features of other diseases. With the aim of enhancing the determination of key etiological factors, we developed and tested a complex disease model that encompasses diverse factors that in combination result in complex diseases. This model was developed to address the challenges of classifying complex diseases given the evolving nature of understanding of disease and interaction and contributions of genetic, environmental, and social factors.

METHODS

Here we present a new approach for modeling complex diseases that integrates the multiple contributing genetic, epigenetic, environmental, host and social pathogenic effects causing disease. The model was developed to provide a guide for capturing diverse mechanisms of complex diseases. Assessment of disease drivers for asthma, diabetes and fetal alcohol syndrome tested the model.

RESULTS

We provide a detailed rationale for a model representing the classification of complex disease using three test conditions of asthma, diabetes and fetal alcohol syndrome. Model assessment resulted in the reassessment of the three complex disease classifications and identified driving factors, thus improving the model. The model is robust and flexible to capture new information as the understanding of complex disease improves.

CONCLUSIONS

The Human Disease Ontology's Complex Disease model offers a mechanism for defining more accurate disease classification as a tool for more precise clinical diagnosis. This broader representation of complex disease, therefore, has implications for clinicians and researchers who are tasked with creating evidence-based and consensus-based recommendations and for public health tracking of complex disease. The new model facilitates the comparison of etiological factors between complex, common and rare diseases and is available at the Human Disease Ontology website.

Asthma Exacerbations in Severe Asthma: Why Systemic Corticosteroids May not Always Be the Best Treatment Option

Purpose

Advances in the management of severe, eosinophilic asthma have improved, but asthma exacerbations continue to occur. This review aims to look at the evidence we have about why exacerbations may occur; their phenotype and why oral corticosteroids may not always be the best treatment option for all exacerbation of symptoms in individuals with severe asthma.

Recent findings

Studies dating back to the 1990s showed that asthma exacerbations across the spectrum of asthma severity were of different inflammatory endotypes. In addition, there is a wealth of evidence suggesting that eosinophilic inflammation is very responsive to corticosteroid therapy, but that non-eosinophilic inflammation is less so. Two recent UK-based studies have undertaken systematic phenotyping of exacerbations in severe asthma and have shown that there are a significant minority of exacerbation events with an increase in asthma symptoms, fall in lung function, but without evidence of raised T2 biomarkers.

Summary

The evidence to date would suggest that T2 biomarker low asthma exacerbations do not benefit from the administration of oral corticosteroids; in fact, the effect of the oral corticosteroids is harmful. However, there is a paucity of data to answer this question directly. Further research is needed to assess the evolution of non-T2 exacerbations not treated with OCS in a randomised, placebo-controlled, manner.

Airway Epithelium: A Neglected but Crucial Cell Type in Asthma Pathobiology

The features of allergic asthma are believed to be mediated mostly through the Th2 immune response. In this Th2-dominant concept, the airway epithelium is presented as the helpless victim of Th2 cytokines. However, this Th2-dominant concept is inadequate to fill some of the vital knowledge gaps in asthma pathogenesis, like the poor correlation between airway inflammation and airway remodeling and severe asthma endotypes, including Th2-low asthma, therapy resistance, etc. Since the discovery of type 2 innate lymphoid cells in 2010, asthma researchers started believing in that the airway epithelium played a crucial role, as alarmins, which are the inducers of ILC2, are almost exclusively secreted by the airway epithelium. This underscores the eminence of airway epithelium in asthma pathogenesis. However, the airway epithelium has a bipartite functionality in sustaining healthy lung homeostasis and asthmatic lungs. On the one hand, the airway epithelium maintains lung homeostasis against environmental irritants/pollutants with the aid of its various armamentaria, including its chemosensory apparatus and detoxification system. Alternatively, it induces an ILC2-mediated type 2 immune response through alarmins to amplify the inflammatory response. However, the available evidence indicates that restoring epithelial health may attenuate asthmatic features. Thus, we conjecture that an epithelium-driven concept in asthma pathogenesis could fill most of the gaps in current asthma knowledge, and the incorporation of epithelial-protective agents to enhance the robustness of the epithelial barrier and the combative capacity of the airway epithelium against exogenous irritants/allergens may mitigate asthma incidence and severity, resulting in better asthma control.

Association between 17q21 variants and asthma predisposition in Pashtun population from Pakistan

OBJECTIVE

Asthma is a heterogeneous and genetically complex respiratory disease, and more than 300 million people are affected worldwide. In this study, frequencies of four SNPs (rs3816470, rs7216389, rs8067378, rs12603332) in chromosome 17q21 region were analyzed and their relationship with the asthma susceptibility, in the Pashtun population of Khyber Pakhtunkhwa province (KPK) of Pakistan were investigated.

METHODS

DNA samples from 500 subjects (asthma cases/controls) were genotyped by Sanger sequencing. Chi-square tests, logistic regression analysis, linkage disequilibrium, and haplotype analysis techniques were applied to study the association of the SNPs with asthma.

RESULTS

Genetic models, including recessive, dominant, co-dominant, over-dominant, and additive, were tested. The frequencies of alleles T/T at rs3816470 (OR = 1.91; 95%CI = 1.15-3.18; p = .011*) and rs7216389 (OR = 2.14; 95%CI = 1.21-3.79; p = .0076*), A/A at rs 8067378 (OR = 1.89; 95%CI = 1.17-3.06; p = .0081*), C/C at rs12603332 (OR = 1.97; 95%CI = 1.18-3.27; p = .008*), under recessive models, respectively, were significantly (p-values < .0125) associated with asthma susceptibility. The frequencies of T/T genotype in rs3816470 (OR = 6.01; 95%CI = 2.48-14.60; p = .000147*), and rs7216389 (OR = 5.05; 95%CI = 1.79-14.21; p = .003296*), and C/C at rs12603332 (OR = 2.64; 95%CI = 1.11-6.32; p = .019063*), were significantly (p-values < .0125) associated with asthma susceptibility in Pashtun women by stratified analysis based on age and gender. Similarly, three unique haplotypes were found associated with disease development and protective effect in female and male subjects. Linkage disequilibrium analysis presented a strong linkage (≥80%) between SNP variants and predicted their co-inheritance in the studied population.

CONCLUSION

The 17q21 variants (rs3816470, rs7216389, rs12603332) were found significantly (p-values < .0125) associated with asthma predisposition in the Pashtun population of KPK exclusively in the female asthmatic cases.

Supplemental data for this article can be accessed.

Exploring the 175-year history of spirometry and the vital lessons it can teach us today

175 years have elapsed since John Hutchinson introduced the world to his version of an apparatus that had been in development for nearly two centuries, the spirometer. Though he was not the first to build a device that sought to measure breathing and quantify the impact of disease and occupation on lung function, Hutchison coined the terms spirometer and vital capacity that are still in use today, securing his place in medical history. As Hutchinson envisioned, spirometry would become crucial to our growing knowledge of respiratory pathophysiology, from Tiffeneau and Pinelli's work on forced expiratory volumes, to Fry and Hyatt's description of the flow-volume curve. In the 20th century, standardization of spirometry further broadened its reach and prognostic potential. Today, spirometry is recognized as essential to respiratory disease diagnosis, management and research. However, controversy exists in some of its applications, uptake in primary care remains sub-optimal and there are concerns related to the way in which race is factored into interpretation. Moving forward, these failings must be addressed, and innovations like Internet-enabled portable spirometers may present novel opportunities. We must also consider the physiologic and practical limitations inherent to spirometry and further investigate complementary technologies such as respiratory oscillometry and other emerging technologies that assess lung function. Through an exploration of the storied history of spirometry, we can better contextualize its current landscape and appreciate the trends that have repeatedly arisen over time. This may help to improve our current use of spirometry and may allow us to anticipate the obstacles confronting emerging pulmonary function technologies.

Emerging role of nutritional short-chain fatty acids (SCFAs) against cancer via modulation of hematopoiesis

The understanding of gut microbiota has emerged as a significant frontier in development of strategies to maintain normal human body's homeostasis and preventing the disease development over the last decade. The composition of the gut microbiota influences the clinical benefit of immune checkpoints in patients with advanced cancer, but the mechanisms underlying this relationship are unclear. Cancer is among the leading causes of mortality worldwide. So far, there is no universal treatment for cancer and despite significant advances, a lot of improvement on cancer therapy is required. Owing to its role in preserving the host's health and maintaining cellular integrity, the human gut microbiome has recently drawn a lot of interest as a target for cancer treatment. Dietary fiber is fermented by the gut microbiota to generate short-chain fatty acids (SCFAs), such as acetate, butyrate, and propionate, which are physiologically active metabolites. SCFAs can modulate the pathophysiology of the tumor environment through various critical signaling pathways. In addition, SCFAs can bind to carcinogens and other toxic chemicals, thus facilitating their biotransformation and elimination through different excretory mechanisms. This review discusses the mechanisms of action of short-chain fatty acids in modulating hematopoiesis of various immune system cells and the resultant beneficial anti-cancer effects. It also provides future perspectives on cancer therapy.

Lipid Nutrition in Asthma

Asthma is a heterogeneous pulmonary disease that has constantly increased in prevalence over the past several decades. Primary symptoms include airway constriction, airway hyperresponsiveness, and airway remodeling with additional symptoms such as shortness of breath, wheezing, and difficulty breathing. Allergic asthma involves chronic inflammation of the lungs, and the rise in its yearly diagnosis is potentially associated with the increased global consumption of foods similar to the western diet. Thus, there is growing interest into the link between diet and asthma symptoms, with mounting evidence for an important modulatory role for dietary lipids. Lipids can act as biological mediators in both a proinflammatory and proresolution capacity. Fatty acids play key roles in signaling and in the production of mediators in the allergic and inflammatory pathways. The western diet leads to a disproportionate ω-6:ω-3 ratio, with drastically increased ω-6 levels. To counteract this, consumption of fish and fish oil and the use of dietary oils with anti-inflammatory properties such as olive and sesame oil can increase ω-3 and decrease ω-6 levels. Increasing vitamin intake, lowering LDL cholesterol levels, and limiting consumption of oxidized lipids can help reduce the risk of asthma and the exacerbation of asthmatic symptoms. These dietary changes can be achieved by increasing intake of fruits, vegetables, nuts, oily fish, seeds, animal-related foods (eggs, liver), cheeses, grains, oats, and seeds, and decreasing consumption of fried foods (especially fried in reused oils), fast foods, and heavily processed foods.

Pediatric Asthma for the Primary Care Physician

In the pediatric population, asthma is the most common chronic disease. Asthma is a chronic inflammatory disease consisting of variable respiratory symptoms and airflow limitation. Proper and timely diagnosis remains of utmost importance. Early diagnosis allows for earlier treatment and subsequent reduction of morbidity and mortality. Newer research and medications have changed the treatment paradigm, including the addition of biologic agents for more severe cases and use of inhaled corticosteroid-formoterol inhaler as a rescue treatment.

Unraveling the therapeutic effects of mesenchymal stem cells in asthma

Asthma is a chronic inflammatory disease associated with airway hyper-responsiveness, chronic inflammatory response, and excessive structural remodeling. The current therapeutic strategies in asthmatic patients are based on controlling the activity of type 2 T helper lymphocytes in the pulmonary tissue. However, most of the available therapies are symptomatic and expensive and with diverse side outcomes in which the interruption of these modalities contributes to the relapse of asthmatic symptoms. Up to date, different reports highlighted the advantages and beneficial outcomes regarding the transplantation of different stem cell sources, and relevant products from for the diseases' alleviation and restoration of injured sites. However, efforts to better understand by which these cells elicit therapeutic effects are already underway. The precise understanding of these mechanisms will help us to translate stem cells into the clinical setting. In this review article, we described current knowledge and future perspectives related to the therapeutic application of stem cell-based therapy in animal models of asthma, with emphasis on the underlying therapeutic mechanisms.

Unravelling the complexity of tissue inflammation in uncontrolled and severe asthma

PURPOSE OF REVIEW

The clinical and inflammatory heterogeneity in asthma constitutes a major challenge for improved treatment. This review describes the nature of the inflammatory complexity and how it can be decoded to yield improved disease understanding and personalized treatment. The focus is on the difficult task of revealing the immunological complexity as it occurs inside diseased patient tissues.

RECENT FINDINGS

The inflammatory heterogeneity in asthma stretches beyond the classical division into allergic Th2 eosinophilic versus Th1 and/or Th17 neutrophilic (or paucigranulocytic) phenotypes. Rather than having one distinct type of inflammation, many patients display a patchwork of overlapping immune signatures. The patient diversity is further increased by differences in regard of distal lung involvement. Faced with this staggering complexity, calls have been made for a pragmatic biomarker-guided identification of treatable traits. In parallel, novel high-dimensional analyses and multiplex imaging aid the long-term goal of decoding the underlying molecular endotypes.

SUMMARY

Asthma is vastly heterogeneous with multiple and superimposed inflammatory and anatomical phenotypes. Despite the intensive research and introduction of highly immune-selective dugs, basic questions remain; especially as still too many of today's uncontrolled patients remain poorly understood. Here, pragmatic biomarker strategies, combined with novel methodological approaches that ultimately reveal the complete immunological complexity, will pave the way for improved differential diagnosis and personalized medication.

Analysis of high-resolution computed tomography phenotypes and pulmonary function in chronic obstructive pulmonary disease

Objective

To explore the correlation between high-resolution computed tomography (HRCT) phenotype and pulmonary function in patients with chronic obstructive pulmonary disease (COPD).

Methods

Fifty-six patients with COPD were retrospectively evaluated using pulmonary function tests (PFTs) and HRCT, and phenotypic pulmonary function parameters were analyzed.

Results

Thirty-one patients were classified as having imaging phenotype A, 11 were phenotype E, and 14 were phenotype M. The total lung capacity (TLC)% of phenotype E was significantly higher than that of phenotypes A and M. The residual volume (RV) to TLC ratio (RV/TLC) in phenotype A was significantly lower than that in phenotypes E and M. The forced expiratory volume in one second percentage (FEV1%) and FEV1/forced vital capacity (FVC) of phenotype A was significantly higher than that of phenotypes E and M.

Conclusion

FEV1/FVC and FEV1% were higher and RV/TLC was lower, indicating less severe emphysema, in patients with phenotype A compared with patients with phenotypes E and M. TLC% of patients with phenotype E was significantly higher than that of patients with phenotypes A and M. The degree of airflow limitation was most severe in patients with phenotype M.

Update in Pediatric Asthma: Selected Issues

Asthma is a complex condition that affects 14% of the world's children and the approach to management includes both pharmacologic as well as non-pharmacologic strategies including attention to complex socioeconomic status phenomena. After an historical consideration of asthma, allergic and immunologic aspects of asthma in children and adolescents are presented. Concepts of socioeconomic aspects of asthma are considered along with environmental features and complications of asthma disparities. Also reviewed are links of asthma with mental health disorders, sleep disturbances and other comorbidities. A stepwise approach to asthma management is discussed that includes pharmacologic and non-pharmacologic strategies in the pediatric population. The role of immunotherapy and use of various immunomodulators are considered as well.

The microbiome in asthma: Role in pathogenesis, phenotype, and response to treatment

OBJECTIVE

To synthesize evidence on the role of microbiota in asthma pathogenesis, phenotype, and treatment outcomes, and to provide perspective on future research directions and challenges.

DATA SOURCES

Studies identified from a PubMed search, including all or some of the terms "asthma," "microbiome," "microbiota," "gut," "airway," "respiratory," "lung," "viral," and "fungal".

STUDY SELECTIONS

Studies included and referenced based on the authors' opinion of the study design and methods, value of the research questions, and the relevance of the results to the objective of the article.

RESULTS

Many studies have demonstrated an important role for intestinal or upper airway microbiota in mediating the pathogenesis of childhood asthma. Fewer but robust studies have implicated a role for lower respiratory tract microbiota in adult asthma phenotype, including effects of treatments. Bacterial and fungal members of the respiratory microbiota are associated with and may drive specific molecular phenotypes of asthma in adults.

CONCLUSION

Current evidence supports the role of human microbiota changes in shaping asthma risk, pathogenesis, and clinical presentation. Further understanding of how microbiota functionally mediate these aspects in clinically relevant contexts will require better integration of advanced scientific tools, analytic methods, and well-designed clinical studies. These efforts should be pursued with a systems-level perspective of the complex interactions between human hosts and their microbiomes, and the impact on these interactions of changes in environmental and lifestyle factors across the lifespan.

German Cockroach Extract Induces Matrix Metalloproteinase-1 Expression, Leading to Tight Junction Disruption in Human Airway Epithelial Cells

PURPOSE

Cockroach exposure is a pivotal cause of asthma. Tight junctions are intercellular structures required for maintenance of the barrier function of the airway epithelium, which is impaired in this disease. Matrix metalloproteinases (MMPs) digest extracellular matrix components and are involved in asthma pathogenesis: MMP1 is a collagenase with a direct influence on airway obstruction in asthmatics. This study aimed to investigate the mechanism by which German cockroach extract (GCE) induces MMP1 expression and whether MMP1 release alters cellular tight junctions in human airway epithelial cells (NCI-H292).

MATERIALS AND METHODS

mRNA and protein levels were determined using real-time PCR and ELISA. Tight junction proteins were detected using immunofluorescence staining. Epithelial barrier function was measured by transepithelial electrical resistance (TEER). The binding of a transcription factor to DNA molecules was determined by electrophoretic mobility shift assay, while the levels of tight junction proteins and phosphorylation were determined using Western blotting.

RESULTS

GCE was shown to increase MMP1 expression, TEER, and tight junction degradation. Both an inhibitor and small interfering RNA (siRNA) of MMP1 significantly decreased GCE-induced tight junction disruption. Furthermore, transient transfection with ETS1 and SP1 siRNA, and anti-TLR2 antibody pretreatment prevented MMP1 expression and tight junction degradation. An extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) inhibitor also blocked MMP1 release, ETS1/SP1 DNA binding, and tight junction alteration.

CONCLUSION

GCE treatment increases MMP1 expression, leading to tight junction disruption, which is transcriptionally regulated and influenced by the ERK/MAPK pathway in airway epithelial cells. These findings may contribute to developing novel therapeutic strategies for airway diseases.

Role of PCDH 1 Gene in the Development of Childhood Asthma and Other Related Phenotypes: A Literature Review

The asthma gene PCDH 1, encoding protocadherin-1, is a cellular adhesion molecule which plays an important role in epithelial barrier formation and repair. PCDH 1 is a novel susceptible gene not only in childhood asthma but also in eczema and other atopic phenotypes. In this article, we reviewed relevant articles from PubMed, Google Scholar, Science Direct and included all available significant pieces of information about the PCDH 1 association with asthma and other atopic or non-atopic phenotypes. It is very interesting that cigarette smoking can induce changes in PCDH 1 expression but how the changes in PCDH 1 induce asthma is still not clear. PCDH 1 gene polymorphism also sometimes plays role in asthma and bronchial hyperresponsiveness (BHR) pathogenesis as well as in allergic dermatitis.

Modeling asthma: Pitfalls, promises, and the road ahead

Asthma is a chronic, heterogeneous, and recurring inflammatory disease of the lower airways, with exacerbations that feature airway inflammation and bronchial hyperresponsiveness. Asthma has been modeled extensively via disease induction in both wild-type and genetically manipulated laboratory mice (Mus musculus). Antigen sensitization and challenge strategies have reproduced numerous important features of airway inflammation characteristic of human asthma, notably the critical roles of type 2 T helper cell cytokines. Recent models of disease induction have advanced to include physiologic aeroallergens with prolonged respiratory challenge without systemic sensitization; others incorporate tobacco, respiratory viruses, or bacteria as exacerbants. Nonetheless, differences in lung size, structure, and physiologic responses limit the degree to which airway dynamics measured in mice can be compared to human subjects. Other rodent allergic airways models, including those featuring the guinea pig (Cavia porcellus) might be considered for lung function studies. Finally, domestic cats (Feline catus) and horses (Equus caballus) develop spontaneous obstructive airway disorders with clinical and pathologic features that parallel human asthma. Information on pathogenesis and treatment of these disorders is an important resource.

Normalizing fibromyalgia as a chronic illness

Fibromyalgia (FM) is a complex chronic disease that affects 3-10% of the general adult population and is principally characterized by widespread pain, and is often associated with disrupted sleep, fatigue, and comorbidities, among other symptoms. There are many gaps in our knowledge of FM, such that, compared with other chronic illnesses including diabetes, rheumatoid arthritis, and asthma, it is far behind in terms of provider understanding and therapeutic approaches. The experience that healthcare professionals (HCPs) historically gained in developing approaches to manage and treat patients with these chronic illnesses may help show how they can address similar problems in patients with FM. In this review, we examine some of the issues around the management and treatment of FM, and discuss how HCPs can implement appropriate strategies for the benefit of patients with FM. These issues include understanding that FM is a legitimate condition, the benefits of prompt diagnosis, use of non-drug and pharmacotherapies, patient and HCP education, watchful waiting, and assessing patients by FM domain so as not to focus exclusively on one symptom to the detriment of others. Developing successful approaches is of particular importance for HCPs in the primary care setting who are in the ideal position to provide long-term care for patients with FM. In this way, FM may be normalized as a chronic illness to the benefit of both patients and HCPs.

Preventive Intra Oral Treatment of Sea Cucumber Ameliorate OVA-Induced Allergic Airway Inflammation

Sea cucumber extracts have potent biological effects, including anti-viral, anti-cancer, antibacterial, anti-oxidant, and anti-inflammation effects. To understand their anti-asthma effects, we induced allergic airway inflammation in mice after 7 oral administrations of the extract. The hyper-responsiveness value in mice with ovalbumin (OVA)-alum-induced asthma after oral injection of sea cucumber extracts was significantly lower than that in the OVA-alum-induced asthma group. In addition, the number of eosinophils in the lungs of asthma-induced mice pre-treated with sea cucumber extract was significantly decreased compared to that of PBS pre-treated mice. Additionally, CD4[Formula: see text]CD25[Formula: see text]Foxp3[Formula: see text]T (regulatory T; Treg) cells significantly increased in mesenteric lymph nodes after 7 administrations of the extract. These results suggest that sea cucumber extract can ameliorate allergic airway inflammation via Treg cell activation and recruitment to the lung.

Lebrikizumab for the treatment of asthma

INTRODUCTION

In asthma, most commonly, 'conventional' anti-inflammatory medications represented by inhaled corticosteroids and leukotriene inhibitors are effective. In some patients however additional inhibition of the airways inflammation is necessary. Such compounds might be molecules inhibiting specifically certain inflammation pathways and lebrikizumab an anti IL-13 molecule might represent a relevant example as a potential asthma therapy.

AREAS COVERED

Discussion of the rationale for the use of lebrikizumab in asthma. Analysis of the related preclinical and clinical data on lebrikizumab in asthma.

EXPERT OPINION

Lebrikizumab demonstrated efficacy in an asthma subset characterized by high serum periostin levels and by heavy eosinophilic inflammation. Phase III data are necessary in order to better position this therapy in asthma including as a potential personalized approach.

Age-Related Changes in Immunological Factors and Their Relevance in Allergic Disease Development During Childhood

Purpose

Allergic diseases are triggered by Th2-mediated immune reactions to allergens and orchestrated by various immunological factors, including immune cells and cytokines. Although many reports have suggested that childhood is the critical period in the onset of allergic diseases and aging leads to alter the susceptibility of an individual to allergic diseases, age-related changes in various immunological factors in healthy individuals as well as their difference between healthy and allergic children have not yet been established.

Methods

We investigated the ratio of Th1/Th2 cells and the levels of 22 allergy-related cytokines across all age groups in individuals who were classified as clinically non-atopic and healthy. We also examined their differences between healthy and allergic children to evaluate immunological changes induced by the development of allergic diseases during childhood.

Results

The Th1/Th2 ratio rose gradually during the growth period including childhood, reaching peak values in the twenties-thirties age group. Th1/Th2 ratios were significantly lower in allergic children than in healthy controls, whereas 14 of 22 cytokines were significantly higher in allergic children than in healthy controls. On the other hand, there were no differences in Th1/Th2 ratios and cytokines between healthy and allergic adolescents.

Conclusions

In this study, age-related changes in Th1/Th2 ratios were found in normal controls across all age groups, and decreases in Th1/Th2 ratio were observed with increasing of 14 cytokines in allergic children. The results of this study may be helpful as reference values for both monitoring immunological changes according to aging in healthy individuals and distinguishing between normal and allergic subjects in terms of immune cells and soluble factors.

Airway Remodeling in Chronic Obstructive Pulmonary Disease and Asthma: the Role of Matrix Metalloproteinase-9

Chronic obstructive pulmonary disease (COPD) and asthma are both associated with airflow restriction and progressive remodeling, which affect the respiratory tract. Among various biological factors involved in the pathomechanisms of both diseases, proteolytic enzymes--matrix metalloproteinases (MMPs)--play an important role, especially MMP-9. In this review, the authors discuss the current topics of research concerning the possible role of MMP-9 in both mentioned diseases. They include the analysis of protein levels, nucleotide polymorphisms of MMP-9 gene and their possible correlation with asthma and COPD. Finally, the authors refer to the studies on MMP-9 inhibition as a new perspective for increasing the effectiveness of treatment in asthma and COPD.

Thiol redox chemistry: role of protein cysteine oxidation and altered redox homeostasis in allergic inflammation and asthma

Asthma is a pulmonary disorder, with an estimated 300 million people affected worldwide. While it is thought that endogenous reactive oxygen species (ROS) and reactive nitrogen species (RNS) such as hydrogen peroxide and nitric oxide, are important mediators of natural physiological processes, inflammatory cells recruited to the asthmatic airways have an exceptional capacity for producing a variety of highly reactive ROS and RNS believed to contribute to tissue damage and chronic airways inflammation. Antioxidant defense systems form a tightly regulated network that maintains the redox environment of the intra- as well as extracellular environment. Evidence for an oxidant-antioxidant imbalance in asthmatic airways is demonstrated in a number of studies, revealing decreased total antioxidant capacity as well as lower levels of individual antioxidants. Thiols in the form of GSH and sulfhydryl groups of proteins are among the most susceptible oxidant-sensitive targets, and hence, studies investigating protein thiol redox modifications in biology and disease have emerged. This perspective offers an overview of the combined efforts aimed at the elucidation of mechanisms whereby cysteine oxidations contribute to chronic inflammation and asthma, as well as insights into potential cysteine thiol-based therapeutic strategies.

Immunobiology of the critical asthma syndrome

It is now recognized that asthma incorporates a broad spectrum of syndromes with varying clinical manifestations. Future improvements in asthma treatment will require a clear characterization of these asthma phenotypes and the cellular mechanisms underlying these clinical manifestations. Herein, we will describe the current knowledge of asthma biology. This will include a review of the early pioneers in asthma and allergy, how this work led to our understanding of TH1 and TH2 cytokines, and the development of the "hygiene hypothesis." We will discuss the utility and limitations of the TH1-TH2 model of asthma in animal and human studies, and how this knowledge addresses controversies surrounding the hygiene hypothesis and other competing models. We will discuss novel therapies that have been developed based on mechanistic understanding of asthma pathobiology, including successes and shortcomings of these therapies. We will review the early work that led to the recognition of "asthma phenotypes." This will include the early discovery of various inflammatory subtypes in asthma and how these inflammatory subtypes correlate with response to therapy. Finally, we will describe recent discoveries in asthma biology that will include the role of the airway epithelium in asthma pathogenesis, novel cytokines important in asthma that may serve as novel therapeutic targets, and the identification of newly described innate immune cells and their role in asthma. Improved understanding of the complex biology underpinning the various asthma phenotypes is critical for our ability to optimize treatment for all patients that suffer from asthma and critical asthma syndromes.

Acute and Chronic Airway Disease After Human Respiratory Syncytial Virus Infection in Cotton Rats (Sigmodon hispidus)

Infection with respiratory syncytial virus (RSV) generally presents as a mild, upper airway disease in human patients but may cause severe lower airway disease in the very young and very old. Progress toward understanding the mechanisms of RSV pathogenesis has been hampered by a lack of relevant rodent models. Mice, the species most commonly used in RSV research, are resistant to upper respiratory infection and do not recapitulate the pattern of virus spread in the human host. To address the need for better rodent models of RSV infection, we have characterized the acute and chronic pathology of RSV infection of a relatively permissive host, cotton rats (Sigmodon hispidus). We demonstrate that virus delivered to the upper airway results in widespread RSV replication in the ciliated respiratory epithelial cells of the nasal cavity and, to a lesser extent, of the lung. Although acute inflammation is relatively mild and rapidly eliminated after viral clearance, chronic, eosinophilic lung pathology persists. These data support the use of cotton rats as a robust rodent model of human RSV disease, including the association between RSV pneumonia and subsequent development of allergic asthma.

Sex steroid signaling: implications for lung diseases

There is increasing recognition that sex hormones (estrogen, progesterone, and testosterone) have biological and pathophysiological actions in peripheral, non-reproductive organs, including the lung. Clinically, sex differences in the incidence, morbidity and mortality of lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, lung cancer and pulmonary hypertension have been noted, although intrinsic sex differences vs. the roles of sex steroids are still not well-understood. Accordingly, it becomes important to ask the following questions: 1) Which sex steroids are involved? 2) How do they affect different components of the lung under normal circumstances? 3) How does sex steroid signaling change in or contribute to lung disease, and in this regard, are sex steroids detrimental or beneficial? As our understanding of sex steroid signaling in the lung improves, it is important to consider whether such information can be used to develop new therapeutic strategies to target lung diseases, perhaps in both sexes or in a sex-specific manner. In this review, we focus on the basics of sex steroid signaling, and the current state of knowledge regarding how they influence structure and function of specific lung components across the life span and in the context of some important lung diseases. We then summarize the potential for sex steroids as useful biomarkers and therapeutic targets in these lung diseases as a basis for future translational research in the area of gender and individualized medicine.

Gene - Gene Interactions Among MCP Genes Polymorphisms in Asthma

Purpose

Monocyte chemoattractant proteins (MCPs) are important cytokines that involved in cellular activation and releasing of inflammatoy mediators by basophils and eosinophils in allergic disease. Some MCP gene variants implicate in asthma and monoclonal antibody for MCP-3 blocks allergic inflammations in the patients with asthma. Detection of interactions between gene and environment or between genes for complex disease such as asthma is important. We searched for an evidence of genetic effect of single nucleotide polymorphisms (SNPs) of MCP genes as well as gene - gene interactions involved in asthma.

Methods

Four hundreds asthmatics and four hundreds normal controls were enrolled. Asthma was defined as a positive bronchodilator response or positive methacholine provocation test with compatible clinical symptoms. Seven MCP gene SNPs (2 SNPs in MCP-1, 1 in MCP-2, and 4 in MCP-3) were included. Association analyses between SNP and asthma, and the tests for gene - gene interaction were performed.

Results

Strong linkage disequilibria were found among 7 MCP gene polymorphisms. There was no SNP that showed a significant association with asthma among 7 SNPs of 3 MCP genes. No haplotype was associated with asthma, either. The combination of MCP1-2518G>A, MCP2+46A>C, and MCP3+563C>T was the best predictive model for asthma as compared to the control in tests for gene - gene interaction. The MCP1-2518G>A and MCP2+46A>C was the second best predictive combination and this had the highest synergistic interaction effect on the subject's status than any other combination of polymorphisms. Complete linkages were not associated with the gene - gene interactions models.

Conclusions

MCP gene polymorphisms probably interact with each other; thus, these findings may help in developing a possible genetic marker to predict asthma.

DNA nanoparticle-mediated thymulin gene therapy prevents airway remodeling in experimental allergic asthma

Thymulin has been shown to present anti-inflammatory and anti-fibrotic properties in experimental lung diseases. We hypothesized that a biologically active thymulin analog gene, methionine serum thymus factor, delivered by highly compacted DNA nanoparticles may prevent lung inflammation and remodeling in a mouse model of allergic asthma. The DNA nanoparticles are composed of a single molecule of plasmid DNA compacted with block copolymers of poly-L-lysine and polyethylene glycol (CK30PEG), which have been found safe in a human phase I/II clinical trial. Thymulin plasmids were detected in the lungs of ovalbumin-challenged asthmatic mice up to 27days after administration of DNA nanoparticles carrying thymulin plasmids. A single dose of DNA nanoparticles carrying thymulin plasmids prevented lung inflammation, collagen deposition and smooth muscle hypertrophy in the lungs of a murine model of ovalbumin-challenged allergic asthma, leading to improved lung mechanics. In the present model of chronic allergic asthma, highly compacted DNA nanoparticles using thymulin analog gene modulated the inflammatory and remodeling processes improving lung mechanics.

Estrogen replacement therapy and asthma

A growing body of clinical and experimental evidence indicates that female sex hormones, particularly estrogen, have significant effects on normal airway function as well as on respiratory disorders, such as asthma. These effects are very complex and are exerted at several levels, directly on airway reactivity or indirectly through regulation of the immune and inflammatory responses in the lung. They can have relevant clinical implications not only according to the phases of the reproductive life in women, but also in relation to the therapeutical administration of estrogen, as in the case of menopausal hormone therapy. Clinical evidence suggests that administration of estrogen to menopausal women is associated with increased rates of newly diagnosed asthma. Conversely, functional studies show that estrogen can improve objective indexes of respiratory functionality.

Ultrastructural changes of airway in murine models of allergy and diet-induced metabolic syndrome

Studying ultrastructural changes could reveal novel pathophysiology of obese-asthmatic condition as existing concepts in asthma pathogenesis are based on the histological changes of the diseased airway. While asthma is defined in functional terms, the potential of electron microscopy (EM) in providing cellular and subcellular detail is underutilized. With this view, we have performed transmission EM in the lungs from allergic mice that show key features of asthma and high-fat- or high-fructose-fed mice that mimicked metabolic syndrome to illustrate the ultrastructural changes. The primary focus was epithelial injury and metaplasia, which are cardinal features of asthma and initiate airway remodeling. EM findings of the allergically inflamed mouse lungs correlate with known features of human asthma such as increased mitochondria in airway smooth muscle, platelet activation and subepithelial myofibroblasts. Interestingly, we found a clear and unambiguous evidence to suggest that ciliated cells can become goblet cells using immunoelectron microscopy. Additionally, we show for the first time the stressed mitochondria in the bronchial epithelia of high-fat- or high-fructose-fed mice even without allergen exposure. These results may stimulate interest in using EM in understanding novel pathological mechanisms for different subtypes of asthma including obese asthma.

Novel therapies in asthma: leukotriene antagonists, biologic agents, and beyond

Asthma is one of the most common conditions seen in clinical practice and carries both a significant disease burden in terms of patient morbidity and a high economic burden in both direct and indirect costs. Despite this, it remains a comparatively poorly understood disease, with only modest advances in treatment over the past decade. Corticosteroids remain the cornerstone of therapy. Both patient compliance with medications and physician adherence to evidence-based guidelines are often poor, and a high percentage of patients continue to have inadequately controlled disease even with optimal therapy. Following a contextual overview of the current treatment guidelines, this review focuses on novel asthma therapies, beginning with the introduction of the leukotriene receptor antagonist zafirlukast in the 1990s, continuing through advanced endoscopic therapy and into cytokine-directed biologic agents currently in development. Along with clinically relevant biochemistry and pharmacology, the evidence supporting the place of these therapies in current guidelines will be highlighted along with data comparing these agents with more conventional treatment. A brief discussion of other drugs, such as those developed for unrelated conditions and subsequently examined as potential asthma therapies, is included.

Lack of association between GTF2H4 genetic variants and AERD development and FEV1 decline by aspirin provocation

Aspirin-exacerbated respiratory disease (AERD) is prevalent in about 10% of asthma patients and is characterized by a severe decline in forced expiratory volume in 1-s (FEV(1) ), an important phenotype for total lung capacity, upon ingestion of aspirin. The general transcription factor IIH subunit 4 (GTF2H4) is positioned at 6p21.33, a part of the major histocompatibility complex (MHC) class II region that contains a number of genes that play an important role in the immune system. In addition, genetic variants in another general transcription factor IIH gene have revealed significant association with lung disease. To investigate whether GTF2H4 genetic variants could be a causative factor for AERD development and FEV(1) decline by aspirin provocation, five common single-nucleotide polymorphisms (SNPs) were genotyped in 93 patients with AERD and 96 aspirin-tolerant asthma (ATA) controls. As a result, when adjusted for age, gender, smoking status and atopy as covariates, the rs1264307 variant and two haplotypes showed nominal signals in the association with AERD (P = 0.02-0.04), but the significances disappeared after corrections for multiple testing (corrected P > 0.05). In further multiple regression analysis, no genetic variants of GTF2H4 showed significant associations with FEV(1) decline by aspirin provocation in asthmatics (P > 0.05). Despite the need for replications in larger cohorts, our preliminary findings suggest that GTF2H4 variants may not be associated with susceptibility to AERD and obstructive symptoms in asthmatics.

Air trapping is a major determinant of persistent airway obstruction in asthmatics

Chronic persistent airway obstruction has been observed in moderate-to-severe asthmatics despite treatment with inhaled corticosteroids. We investigated which airway changes were associated with this obstruction. High-resolution computed tomography (HRCT) was performed at study entry and reexamined at the time of follow-up when the FEV1 reached a maximally constant level after treatment for 1 year or more with inhaled corticosteroids. Bronchial wall area and air trapping extent were compared in the recovered group (n = 18) and the persistent airway obstruction group (n = 14). Bronchial wall area and air trapping of the initial HRCT were similar between the two groups. On follow-up HRCT, air trapping was markedly decreased in the recovered group compared with that on initial HRCT (P = 0.017), whereas bronchial wall area did not change. In the persistent-airway-obstruction group, these two parameters did not change during follow-up. When follow-up HRCT was compared, air trapping was significantly greater in the persistent-airway-obstruction group than in the recovered group (P = 0.003). Difference post-bronchodilator FEV1 value between at initial and 2nd HRCT exam was correlated with difference air trapping value between at initial and 2nd HRCT exam(%) on the follow-up HRCT (P = 0.017). The presence of persistent airflow obstruction were significantly associated with the air trapping % difference between initial and 2nd time (RR = 1.70, P = 0.018). Persistence of AT could be a main contributing factor to chronic persistent airflow obstruction in asthma.

Relationship between group-specific component protein and the development of asthma

RATIONALE

Airway inflammation and remodeling during asthma are attributed to the altered expression of biologically relevant proteins.

OBJECTIVES

To search for asthma-specific proteins in bronchoalveolar lavage fluid (BAL) from individuals with asthma and to validate the identified proteins in an experimental model of asthma.

METHODS

Liquid chromatography-tandem mass spectrometry was performed to identify proteins in BAL fluid found by two dimensional electrophoresis (2DE) to be differentially expressed in subjects with asthma versus control subjects. Group-specific component (Gc) and mRNA levels were measured using an ELISA, Western blots, and PCR. A neutralization study using an antibody against Gc protein was performed in an experimental asthma model.

MEASUREMENTS AND MAIN RESULTS

Based on 2DE, 15 proteins were significantly up-regulated or down-regulated in eight subjects with asthma compared with eight control subjects. The protein levels of Gc, hemopexin, and haptoglobin-b were increased, whereas the a1- antitrypsin and glutathione S-transferase levels were decreased in subjects with asthma. The Gc concentration in BAL fluid was significantly elevated in 67 subjects with asthma compared with that in 22 control subjects (P < 0.009). The Gc was significantly correlated with the neutrophil percentage in BAL fluid of subjects with asthma (P = 0.001). Gc mRNA and protein levels were higher in ovalbumin-sensitized/ challenged asthma mice than in sham-treated mice. Gc protein were expressed on alveolar macrophages and on epithelial cells. Treatment with an anti-Gc antibody dose-dependently reduced the ovalbumin sensitization/challenge-induced enhancement of airway hyperreactivity, airway inflammation, goblet cell hyperplasia,and levels of eotaxin, interleukin-4, -5, and -13, and interferon-g.

CONCLUSIONS

Gc may be involved in the development of asthma, and the neutralization of Gc protein could be a therapeutic strategy for asthma.

The association of a single-nucleotide polymorphism of the IL-2 inducible T-cell Kinase gene with asthma

Asthma manifests as TH2-dominant airway inflammation regulated by inducible T-cell kinase (ITK). To investigate associations between genetic variants of the ITK gene and asthma, 31 single-nucleotide polymorphisms (SNPs) were genotyped in 303 normal controls and 498 asthmatics and the two groups were compared using logistic regression models. The functional effects of the ITK promoter SNP were assessed using pGL3 luciferase reporter systems and gel-shift assays. The minor allele-196C>T in the promoter region of the ITK gene was significantly more frequent in asthmatics than in controls. The luciferase activity of the PGL3-ITK-196T allele construct was higher than that of the -196C allele. In the gel-shift assay, -196T double-stranded oligonucleotides bound more strongly to Jurkat cell nuclear protein compared to the -196C double-stranded oligonucleotides. People with the -rare allele 196C>T may be more susceptible to asthma via transcriptional regulation of the ITK gene.